360 SCIENTIFIC CONGRESS OF CARLSRUHE. 



of his youth and scientific career. The oral lecture of M. Erdmami 

 brought to the notice of the section several new facts verified in his 

 laboratory : 



First. Vesicatory Principle of the Ranunculus Sceleratus.- — This prin- 

 ciple presents itself under the form of an acrid oil which, in the end, 

 changes into a white mass composed of anemonine and of anemonic 

 acid. This transformation takes place in the plant even when sub- 

 jected to desiccation, and the vegetable, in consequence of it, loses all 

 its acrimony. 



Second. Action of some Metallic Salts on Ligneous Substances. — It is 

 a customary practice to preserve wood, and especially the sleepers of 

 railways, by impregnating them with certain metallic solutions, and 

 among others, the solution of sulphate of copper; for these saline 

 substances form with the wood a species of combination which appear 

 sufficiently intimate to resist the action of water, and wood thus pre- 

 pared may, in effect, be sunk in water without abandoning to it' the 

 copper which is held in combination. Now, this is not the case when, 

 instead of wood in its normal condition, we -employ purified ivood; 

 that is to say, cellulose. Impregnated with sulphate of copper, the 

 cellulose becomes colored, indeed, but at the slightest lavage with 

 water, it resigns the sulphate which it seemed to have fixed. 



Examining this fact a little more closely, we recognize that, in order 

 that wood should Jbe capable of fixing the sulphate of copper, it must 

 necessarily be resinous. Moreover, it is known that weak solutions of 

 the sulphate of copper remove azotised substances from wood. 



Third. Solubility of the sulphate of baryta. — The sulphate of baryta 

 is one of the salts on which water has the least action ; but if this sul- 

 phate is insoluble in pure water, it becomes soluble when this last con- 

 tains nitrate of ammonia ; a concentrated solution of that salt even dis- 

 solves considerable proportions of it. This solution remains limpid 

 in presence of the chlorides of potassium, of ammonia, of strontium, 

 and of calcium, but it is rendered turbid by salts of which the base is 

 baryta. Water added, even, in great quantities, has no action on it. 

 This solubility of the sulphate of baryta in the nitrate of ammonia is 

 considerably augmented when we add to this last a little chlorhydric 

 acid ; in which case the dissolving agent is the chlorine, resulting from 

 the decomposition of chlorhydric acid. 



From the fact that at this first sitting of the section the list of de- 

 signated speakers was small, an opportunity was afforded for objec- 

 tion, and several lively and instructive discussions arose on the part 

 of the members ; but from the 18th of September, the order of the day 

 being fuller, and the sessions restricted to two hours, little questioning 

 could take place, and the speakers, whose names had been enrolled, 

 were required to succeed one another with as much rapidity as pos- 

 sible. 



